Differently from the manifold-templates which incorporate structures of large dimensions, such as arms, the system hereunder proposed, according to this invention, offers as advantages, in relation to the manifold-template mentioned above, the full flexibility in relation to the slope of the sea-bottom, without the need for the provision of alignment devices to correct deviations in well drilling, such as universal joints, loops and active connectors between the wet christmas tree (WCT) and the manifold-template. This invention is free from problems caused by drilling cuttings, without the need for the provision of equipment for debris dispersion, or space for the accumulation of debris which imply the separation of the manifold-templates from the ground. The invention allows for early drilling in relation to template installation, which renders the system advantageous even in water depths allowing for the use of guide-cables. The present invention does not require the provision of contingency mouths, since the wells do not integrate the structure. The apparatus of the invention allows for easy access of ROV for inspection and operation of valves in the manifold and in the WCTs as a function of the distance between the same. The subsea production system allows for higher operational safety, as a function of the larger distance between the WCTs and the manifold, thereby drastically reducing the risk of damages caused by collision and dropping of objects, particularly in operations without guide-cables. The system of the invention presents a simpler structure, by not requiring arms, nor suffering from the influence of stresses originating from the wells. The system allows for simpler operation with lower costs, even of the drilling rig itself. In certain cases the system does not require piling or levelling. The elements of the system may be set on the sea-bottom, which allows, in opposition to the use of templates, the retrieval of the elements at the end of the project, leaving the sea-bottom clear and permitting reinstallation in another location, or upon retrieval, maintenance of the components. The connection between the satellite wells and the manifold depends upon the height of the manifold structure in relation to the marine ground. The traditional methods of connection, such as pull-in, are significantly impaired by the structure height of the manifold structure. The connection between the satellite wells and the manifold is little affected by the configuration of the marine ground. A larger number of wells may be interconnected to the system for identical dimensions to that of a manifold-template with arms, since the area required for connecting a satellite well to the manifold by the methods hereunder proposed is much smaller than the area occupied by a well of the template. The invention permits utilization of flexible lines of lower cost, due to the expectancy of stresses which are much smaller than those of the traditional lay-away methods which involve large line lengths. The system utilizes christmas trees used in satellite wells and already tested in large water depths, etc.
In comparison with a manifold with satellite wells located at large distances, the system hereunder proposed offers the major advantage of economy in lines and installation costs, as well as reducing drastically, the risks of paraffin deposition in the lines as a function of the reduced line length exposed to the low sea-bottom temperatures in large water depths.